A stroke position adjusting assembly is required in case of eccentric, crank or wedge presses or the like in order to allow to adjust the thickness of the workpieces as well as their exact dimensional accuracy, it being necessary to consider that differences in thickness may be due to frame elongation, variations in temperature of the machine and tool and tool wear. An adjusting assembly is required to adapt the stroke position to said changing marginal conditions.
For changing the stroke position of a ram with respect to the press bed, it has been known to use an eccentric bushing for a pressure transmission bolt provided at its circumference with a worm toothing engaged by a worm of the adjusting means, it being possible to fix the eccentric bushing by a clamping device. In case of the known stroke position devices, the adjusting operation, i.e. releasing the bracing of the eccentric bushing and setting it, takes a relatively large amount of time. In other words, it is necessary to interrupt for a longer or less long time the operation of the metal forming machine in view of the setting of the stroke position, whereby the machine output is reduced.